He denied trying to slip extravagant expenses and business ventures past Sydney Water as reimbursable costs incurred for building water infrastructure around the city's north-west.

"You came in there and immediately formed the view that you would milk it. Milk it and get every cent you could get out of Sydney Water Corporation, is that right?" counsel assisting Geoffrey Watson SC said.

"I reject that, Mr Watson," Di Girolamo said.

"And you recognised immediately that the way that the arrangement could be milked was by putting inappropriate claims to Sydney Water in the hope they never picked them up, in the hope that they would pay them without picking them up," Watson continued.

Di Girolamo agreed Sydney Water should never have been asked to foot the bill for limousine travel, luxury accommodation, Italian Chamber of Commerce donations or on-air advertising for AWH on Macquarie Radio.

All of these expenses must have been signed off by mistake, Di Girolamo said.

He denied "stonewalling" senior Sydney Water bureaucrats when they requested invoices and receipts.